This disclosure relates generally to guidewires, and more particularly, to a system and method of integrating electromagnetic microsensors into interventional endovascular devices (guidewires) for tracking the guidewires within vessels of the body with a surgical navigation system.
Guidewires are used in the body, particularly the vascular system in endovascular applications. Guidewires are used to aid in the insertion of catheters into the body and to evaluate the vessel along which the catheter will travel. In general, a guidewire is inserted into a body system such as the vascular system at the point of entry, which is usually a small percutaneous incision in the arm, leg or groin, and advanced through the lumen in one or more blood vessels to the target site. A generally hollow cylindrical catheter is slipped over the guidewire and directed to the target site by following the guidewire. The catheter doesn't have the stiffness or rigidity of the guidewire. The guidewire and catheter must be precisely and efficiently positioned at a predetermined location within the blood vessel in order to most effectively treat the underlying medical condition.
Surgical navigation systems track the precise location of surgical instruments in relation to multidimensional images of a patient's anatomy. Additionally, surgical navigation systems use visualization instruments to provide the surgeon with co-registered views of these surgical instruments with the patient's anatomy. Surgical navigation systems may be based on any known tracking technology such as, for example, electromagnetic tracking technology. The surgical navigation system determines the position and/or orientation of a microsensor within a surgical instrument (e.g., a guidewire or a catheter) and conveys this location to a user. The position and orientation information can be conveyed by virtually superimposing a graphic representation of a portion of the surgical instrument onto a patient image. The surgical instrument can be viewed in real-time or near real-time as it passes through the patient. Accordingly, the user receives visual feedback to help navigate or guide the surgical instrument to the target site.
There are clinical benefits to electromagnetically tracking a portion or entire length of a guidewire that is used in endovascular interventional applications. One benefit is that a user can more efficiently navigate a guidewire to the target site with the aid of a three-dimensional (3D) surgical navigation tracking system. Another benefit is that the tracking system will provide real-time location data of the guidewire to the user, requiring a lower radiation dose from the imaging apparatus.
It is very difficult to incorporate electromagnetically trackable sensors of high signal strength into devices of the sizes provided by typical guidewires having a diameter of less than a 1 mm. These electromagnetically trackable sensors may require a shielded type of electrical connection (e.g., coax or twisted pair) with the surgical navigation tracking system to reduce the introduction of noise into the electromagnetic signal. The sensors must efficiently occupy the volume available to maximize signal strength without affecting the clinical and mechanical performance of the guidewire. The guidewire must be robust for the clinical applications contemplated and the electromagnetically trackable sensors must have minimal impact on the mechanical performance of the guidewire, especially with regards to pushability and steerability.
Therefore, it is desirable to provide a guidewire with rugged integration of a plurality of electromagnetically trackable microsensors into a guidewire with minimal impact on the performance of the guidewire during clinical applications.